Lake Rotoiti is a lake in the Bay of Plenty region of

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

. It is the northwesternmost in a chain of lakes formed within the Okataina Caldera. The lake is close to the northern shore of its more famous neighbour, Lake Rotorua, and is connected to it via the Ohau Channel. It drains to the Kaituna River, which flows into the Bay of Plenty near

Maketu Maketu is a small town on the Bay of Plenty Coast in New Zealand. Maketu is located in the Western Bay of Plenty, New Zealand. Maketu has an estuary from which the Kaituna River used to flow. It is also adjacent to Newdicks Beach located on t ...

. The full name of the lake is Te Rotoiti-kite-a-Īhenga, which in the

Māori language Māori (), or ('the Māori language'), also known as ('the language'), is an Eastern Polynesian language spoken by the Māori people, the indigenous population of mainland New Zealand. Closely related to Cook Islands Māori, Tuamotuan, and ...

means "The Small Lake Discovered By Īhenga", the

Māori Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the C ...

explorer also credited with discovering Lake Rotorua. Legend says that the lake was named as such because when Ihenga first saw it, he was only able to see a small part of it and thought the lake was a lot smaller. Since the 1960s, the quality of lake water has been negatively affected by inflows of nitrogen rich water from Lake Rotorua, agricultural run-off from surrounding farms and seepage from domestic

septic tanks A septic tank is an underground chamber made of concrete, fiberglass, or plastic through which domestic wastewater (sewage) flows for basic sewage treatment. Settling and anaerobic digestion processes reduce solids and organics, but the treatme ...

. The effects of this included an almost permanent algal bloom in the Okere arm of the lake and choking lake weed growth in other still areas of the lake. A barrier to divert the nutrient rich waters of Lake Rotorua into the Kaituna River was completed in late 2008. The Bay of Plenty Regional Council expected to see improvement in lake water quality within five years and the Rotorua Te Arawa Lakes Program reported in 2013 that the intervention has significantly improved water quality. Water quality is the highest it has been in decades, on track to meet targets set by the Program to meet community expectations. Lake Rotoiti has thermal hot-spring baths on the southern shore which are accessible by boat.

Geology

Its joint drainage with

Lake Rotoroa Lake Rotoroa (Māori: "long lake") may refer to the following New Zealand lakes: * Lake Rotoroa (Northland) * Lake Rotoroa (Tasman) * Lake Rotoroa (Hamilton, New Zealand) (or "Hamilton Lake"), Hamilton City, Waikato, New Zealand * Lake Rotoroa (W ...

through the Ohau Channel depends upon the sinking Tikitere

graben In geology, a graben () is a depressed block of the crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German, meaning 'ditch' or 'trench'. The word was first used in the geologic contex ...

which is also very geothermally active on the south eastern margins of the lake. The Rotoiti eruptive vents are at the eastern end of the lake and define the north western margins of the

Haroharo Caldera The Haroharo Caldera (Haroharo volcanic complex) is a postulated volcanic feature in Taupō Volcanic Zone of the North Island, New Zealand within the larger and older Ōkataina Caldera. Since 2010 further studies have tended to use the terms Har ...

in the

Ōkataina Caldera Ōkataina Caldera (Ōkataina Volcanic Centre, also spelled Okataina) is a massive, recently active volcanic caldera and its associated volcanoes located in Taupō Volcanic Zone of New Zealand's North Island. It is just east of the smaller Rotoru ...

. The age of this large eruption of more than of magma was historically ill defined due to several complexities and the literature gives a range from 40,000 years to 64,000 years ago with 47,400 ± 1500 years ago being most recently quoted. What is not now challenged is that this was a paired eruption with a nearby vent in the

that had a separate magma source and erupted Earthquake Flat

breccia Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of di ...

.Houghton B F, Wilson C J N, McWilliams M O, Lanphere M A, Weaver S D, Briggs R M, Pringle M S, 1995
Chronology and dynamics of a large silicic magmatic system: Central Taupo Volcano Zone, New Zealand
Geology, 23: 13-16.

References

{{DEFAULTSORT:Rotoiti, Lake, Bay of Plenty Lakes of the Bay of Plenty Region Okataina Volcanic Centre Volcanic crater lakes